Use of web applications in our day to day life are increasing, which result in an increase in the amount of sensitive data transmitted over the Internet. Sensitive data can be transmitted securely over the Internet by encrypting them. Among several public key cryptosystems elliptic curve cryptosystem is a recent one. This cryptosystem gives us stronger security with smaller key size, thus making it useful in those devices which have limited memory and power consumption ability. Encoding of text messages into elliptic curve points and decoding encoded points into original plaintext is always challenging in ECC. General approach for message mapping is to encode the characters of a message into the x-Coordinate of a point on an elliptic curve Ep (a, b). Then find out corresponding y value so that (x, y) lies on Ep (a, b). The point is then encrypted and transmitted. Since for every point both x and y values are to be transmitted and for stronger security, value of p is of at least 160 bits in today’s standard, therefore a major concern is to diminish the number of bits used in mapped point (x, y). In this paper we will discuss about a new mapping methodology of a group of alphanumeric characters into an elliptic curve point which reduces the number of bits to be transmitted without compromising the data security.

Elliptic Curve, Mapping algorithm, encoding, decoding, encryption, decryption

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